ARP 425 Head Studs Torque
Ordered a set of ARP head studs for my 2012 6.7 Cummins.
Did quite bit of research before the purchase.
Since I'm not planning on an all out build I opted for the 425 set. As far as the re-torque goes I'm reading different opinions.
On a different forum someone posted that he wasn't comfortable doing the install himself so he had a shop do it.
They torqued the head studs to 135lbs instead of 125lbs and adjusted the valves and let it go without the re-torque.
No problems. I'll follow the procedure of incrementally getting to proper torque and the proper sequence of tightening the studs.
I've also read of loosening and retorquing up to 5 times. Like to get you folks opinions.
Thanks,
Mac H.
Re: ARP 425 Head Studs Torque
I installed my own and did the initial torque valve lash and never retorqued and I haven't had any problems been almost 10k miles.
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Re: ARP 425 Head Studs Torque
That's my way of thinking also.
On this web site there's an old thread comparing the 425 to the 625 studs that has a post saying he went through a period of time, pulled the VC, checked torque and valve lash and both were good to go.
My main question is about the increase of final torque. I know Ray has a very good step by step post on the installation of the 625s.
Thanks for the reply.
Mac H
Re: ARP 425 Head Studs Torque
He does have a great post on the install but the headstuds should come with installation instructions from ARP for the proper torque specs and instructions.
Now is you change one bolt out and install one stud at a time you can go to the full torque spec initially because the head is already torqued to spec; but it will not hurt to go thru the stages of torquing for all studs.
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Re: ARP 425 Head Studs Torque
Quote:
Originally Posted by
Western
Now is you change one bolt out and install one stud at a time you can go to the full torque spec initially because the head is already torqued to spec; but it will not hurt to go thru the stages of torquing for all studs.
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This is incorrect. The factory bolts have a torque spec of 89ftlbs + 90 degrees. Torque spec for ARP 425s is 125ftlbs. Some folks go to 130 or as high as 135. Do that at your own risk.
You should replace a bolt, torque that stud to 100ftlbs, then move to the next one in sequence. When you've replaced the last bolt, and torqued to 100ftlbs, start the cycle over at 110ftlbs, then 120, then 125-130. You torque incrementally to ensure the most even clamping force is applied to the gasket
Re: ARP 425 Head Studs Torque
Quote:
Originally Posted by
ZeroSignal
This is incorrect. The factory bolts have a torque spec of 89ftlbs + 90 degrees. Torque spec for ARP 425s is 125ftlbs. Some folks go to 130 or as high as 135. Do that at your own risk.
You should replace a bolt, torque that stud to 100ftlbs, then move to the next one in sequence. When you've replaced the last bolt, and torqued to 100ftlbs, start the cycle over at 110ftlbs, then 120, then 125-130. You torque incrementally to ensure the most even clamping force is applied to the gasket
^^. Correct on this method.
I did my 425’s in this fashion and have not ever re torqued them.
The instruction manual from ARP does not call for re torquing and I’ll trust their instructions.
Be sure you use the appropriate ARP ultra torque lubricant for the threads and washers and you should be good to go.
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Re: ARP 425 Head Studs Torque
Quote:
Originally Posted by
InlineSix.7
^^. Correct on this method.
I did my 425’s in this fashion and have not ever re torqued them.
The instruction manual from ARP does not call for re torquing and I’ll trust their instructions.
Be sure you use the appropriate ARP ultra torque lubricant for the threads and washers and you should be good to go.
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X2- think of it like putting a wheel/tire on your truck. You torque straight across and make several passes around the entire rim/tire to make sure it’s even and tight.
Personally, I would follow instructions in the kit and info in this short thread and forget the rest.
If you want to over-torque for more holding power I would recommend just going with the 625s vs stretching 425s/2000s.
Re: ARP 425 Head Studs Torque
Quote:
Originally Posted by
ZeroSignal
This is incorrect. The factory bolts have a torque spec of 89ftlbs + 90 degrees. Torque spec for ARP 425s is 125ftlbs. Some folks go to 130 or as high as 135. Do that at your own risk.
You should replace a bolt, torque that stud to 100ftlbs, then move to the next one in sequence. When you've replaced the last bolt, and torqued to 100ftlbs, start the cycle over at 110ftlbs, then 120, then 125-130. You torque incrementally to ensure the most even clamping force is applied to the gasket
Excellent!
Makes good sense.
Thanks for the reply.
Re: ARP 425 Head Studs Torque
Quote:
Originally Posted by
ZeroSignal
This is incorrect. The factory bolts have a torque spec of 89ftlbs + 90 degrees. Torque spec for ARP 425s is 125ftlbs. Some folks go to 130 or as high as 135. Do that at your own risk.
You should replace a bolt, torque that stud to 100ftlbs, then move to the next one in sequence. When you've replaced the last bolt, and torqued to 100ftlbs, start the cycle over at 110ftlbs, then 120, then 125-130. You torque incrementally to ensure the most even clamping force is applied to the gasket
Took me a while to find this, but exactly what I was looking for!
Thanks for the great info on the torque sequence!
